Monday, November 08, 2010

Diesel from Waste Plastics Scales Up in UK and Ireland

STA UK is gearing up to build 10 new waste plastic to diesel plants in the UK. The first plant is to be built in Port Laoighise, Ireland. The process utilises pyrolysis (heating in absence of oxygen) of waste plastics, with fractional distillation of the pyrolysis gases to purify the diesel.

Plastic waste is continuously treated in a cylindrical chamber and the pyrolytic gases condensed in a specially-designed condenser system to yield predominantly straight chain aliphatic hydrocarbons with little formation of by-products. These hydrocarbons are then selectively condensed and cleaved further catalytically to produce the average carbon chain length required for distillate fuel.

The plastic is pyrolized at 370 ºC-420 ºC and the pyrolysis gases are condensed in a 2-stage condenser to produce a low-sulfur distillate. (Pyrolysis is a process of thermal degradation in the absence of oxygen.) _GCC

The problem with the production of butanol is that current micro-organisms cannot tolerate more than a few per cent concentration of butanol, and die off before they can produce appreciable yield. So either Butamax will have to develop hardier organisms, or they will need to find an efficient way to pull the butanol out of solution as quickly as it is produced. Additional solutions to the problem might include a staged platform of multiple microbes or "pseudo-microbes" (catalytic platforms which perform the essential synthesis operations of the microbe without the cells). Each stage might perform a separate step in the synthesis process, with each stage adapted to its own set of reactants and products to minimise toxicity for that particular stage.